Approved by Chris:

$ svn merge -c 113257 https://llvm.org/svn/llvm-project/llvm/trunk
--- Merging r113257 into '.':
A    test/Transforms/InstCombine/sqrt.ll
D    test/Transforms/InstCombine/2010-07-19-sqrt.ll

Renaming test.

$ svn merge -c 113260 https://llvm.org/svn/llvm-project/llvm/trunk
--- Merging r113260 into '.':
U    test/Transforms/InstCombine/sqrt.ll
U    lib/Transforms/InstCombine/InstCombineCasts.cpp

Log:
Fix a serious performance regression introduced by r108687 on linux:
turning (fptrunc (sqrt (fpext x))) -> (sqrtf x)  is great, but we have
to delete the original sqrt as well.  Not doing so causes us to do 
two sqrt's when building with -fmath-errno (the default on linux).

llvm-svn: 113265